Hello.
On my dual boot computer, system try to mount windows 10 partition system which has no mount point.
This a fresh install.
That is very new to me.
Authentication required
Yast partitioner
fstab
Any help is welcome.
Check Plasma systemsettings->removable storage-> removable devices and disable automatic mounting…
If this doesn’t help you can also add this partition to fstab and add the noauto flag.
Or is it the /win_linux_exchange_1 ntfs partition?
To mount a Windows partition you must have fast boot OFF in Windows. This leave all Windows in a unmountable state.
How is this related to the TOs problem? It is a standard Plasma dialogue which tries to mount a partition, but as the user flag is not set it asks for the admin passwort. So that happens if you have checked the box for automount in Plasma systemsettings…
My read is that the mount fails, OP was not real clear
If you look at the provided picture and are a Plasma user you will know this problem 
The removable device dialogue from Plasma can mount devices which are not present in fstab. But for that it shows the admin/root password dialogue (logical). This can confuse some users, that Plasma tries to mount a device which is not present in fstab…
With this setting, everytime you start your machine, this mount dialogue pops up.
This also happens on some dualboot machines, that if you update grub, plasma asks to mount the drive from the other OS as it want’s to update the grub config…
Uncheck the box “on login” and “on attach” at the top of the window. After that you can uncheck partitions you don’t want to mount automatically. After that check the boxes at the top again.
If you don’t know which partition your /dev/sda3 is, issue an
sudo blkid
I am not trying to mount windows 10. I am just booting on leap 15.4
I know what partition is /dev/sda3.
It is windows 10 partition as said in post #1
Then do what i described in this post System try to mount windows 10 partition - #9 by hui
But don’t check the boxes for “All known devices” again as it will overwrite the settings in the lower part of the window…
Please follow the hints…
Also check the “disconnected devices”
Only you can tell as you should be able to make a connection between name, label, UIID, and mount point of a partition…
Initial problem is solve
fstab file is what it should be.
Thank you very much.
Please show
cat ~/home/USERNAME/.config/kded_device_automounterrc
USERNAME needs to be replaced by your current user name.